physiology of a Wilty pea: abscisic acid production under water stress

‘Wilty’ (JI 1069), a mutant of Pisum sativum, has been examined for its ability to produce abscisic acid (ABA) under water stress. ABA was measured using combined gas chromatography-mass spectrometry and multiple-ion-monitoring employing a deuterated internal standard. In intact droughted plants, ‘Wilty’ produced less ABA than a non-wilty line (JI 1194) and maximum production was delayed. Detached leaves of the wilty mutant lost significantly more water than control leaves but did not show an increase in ABA content. Non-stressed mutant material from both intact plants and isolated leaves contained less ABA than control tissue.